Works for RD200 Version 2 units with serial numbers starting with either FR:RU (United States) , FR:RE (Spain) , FR:GI and FR:HA (??? both sold in the US). Now works for version 1 (FR:R2 serial numbers). V1 integration currently only supports current radon value, 1 day and 1 month readings. Note the box and the device display do not show the "FR:" portion of the serial number.

If you are pretty sure it is a version 2 device, but has a differnet serial number prefix, edit the manifest.json and line 152 in config_flow.py to include you prefix. If it works, post an issue or a PR and I can add it in.

A python script is posted for people to help find important fields in the V2.

If use ESPHome BT proxy, update to at least ESPHome 2022.12.4 to allow Version 2 radon peak value to work correctly.

Installation Instructions

Add this repo into HACS
Install integration
Restart Homeassistant
Wait a few minutes and HA should find it automatically
If not found automatically, Go to Settings->Device and Services->Add Integration (blue button at bottom right) -> search for RD200
It should find it and set it up

Note: If used the ESPHome integration in the past, you must remove the RD200 MAC address from the ble_client: section.

Version 2 Data locations:

Reading	Write Value	Data Location	Data Format	Unit	Added in Integration
`Current Radon`	`0x50`	`data[2:4]`	little endian ushort	Bq/m³	Yes
`Average Day Radon`	`0x50`	`data[4:6]`	little endian ushort	Bq/m³	Yes
`Average Month Radon`	`0x50`	`data[6:8]`	little endian ushort	Bq/m³	Yes
`Peak Radon`	`0x40`	`data[51:53]`	little endian ushort	Bq/m³	Yes
`Serial`	`0x40`	`data[8:11] + data[2:8] + data[11:15]`	chars		No
`Model`	`0x40`	`data[16:21]`	chars		No
`Firmware`	`0x40`	`data[22:30]`	chars		No
`Uptime Minutes Field`	`0x51`	`data[4:6]`	little endian ushort	minutes	Yes
`Uptime Miliseconds Field`	`0x51`	`data[3:5]` I think this is wrong, but who cares!	little endian ushort	miliseconds	Yes